Fabric care compositions comprising dispersed lamellar phases are typically not miscible with perfume oils. However, perfuming the fabric compositions is essential to secure high consumer acceptance. Fabric care compositions with a pleasant neat product odor that also deliver a pleasant odor through the wash process and ultimately to dry fabrics are far more desirable to the consumer than un-perfumed fabric care products. The typical and conventional method of perfuming a fabric care composition comprising dispersed lamellar phases is to combine the perfume and the fabric care composition and apply a high level of mechanical energy until the perfume oil is subdivided and adsorbed by the lamellar species. The need to use a high level of mechanical energy leads to several problems. Compositions comprising lamellar phases are typically colloidal dispersions that are not thermodynamically stable. It is desirable for the fabric care composition comprising dispersed lamellar phases to be homogeneous in order to provide the consumer with uniform, acceptable performance with minimal consumer intervention (e.g. shaking the product to recombine phases). When such colloidal dispersions of lamellar phases are exposed to high mechanical energy to incorporate perfume, these compositions may become unstable and separate or form a high viscosity composition. Compositions that separate or form high viscosity phases are unacceptable because these compositions often have poor pour properties, inconsistent performance and/or an undesirable visual appearance.
Additionally the equipment needed to apply high mechanical energy is capital intensive and so such equipment is not always available to provide the level of energy needed to incorporate perfume, especially in economically developing geographies.
Alternately, in place of high mechanical energy, the process engineer may employ the tactic of adding perfume into the front end of product making or increase the residence time of the product in the mixing tank to thoroughly incorporate the perfume. While both approaches will increase the likelihood of perfume incorporation even with many perfumes that are difficult to incorporate, these approaches introduce other problems. Incorporating perfume at the beginning of product making of processing reduces flexibility and introduces a need for increased capital for storage of product variants. Also when perfume is incorporated in the front-end of a process, it is often introduced when other components are still hot and thus, a portion of the perfume volatiles can be lost resulting in sub-optimal product and wasted perfume materials. Increased residence time in the mixing tank is not a desirable solution as it reduces the product making capacity leading to shortfalls in shipping and increased manufacturing costs. Increasing the residence time in mixing tanks increases cycle time to make the product which effectively increases the costs associated with product making.
In today's marketplace, the consumer demands increased customization. This requires processing facilities to be more flexible than ever. Thus it is important to have the capability to differentiate a basic (or base) fabric care formulation just prior to packaging in order to simultaneously achieve maximum efficiency and customization capability. The present invention introduces a method of incorporating perfume at the back-end of product making that requires only simple low-energy mixing (e.g., static mixer).
An additional problem faced when making perfumed fabric care products is that some perfumes are much more difficult to incorporate into fabric care compositions comprising dispersed lamellar phases. Such perfumes are typically less polar perfumes (as further herein described below) are poorly incorporated or impossible to incorporate even after very high levels of mechanical energy are applied. Alternately, certain perfumes can be excluded from use based on poor incorporation related to the perfume's physical properties, but this approach limits the perfumer's and formulator's ability to make the best product and it limits the range of offerings available to satisfy the consumer's demands for customization in fabric care products.
Other challenges are presented by compositions comprising low level of dispersed lamellar phases. Such compositions are exceptionally difficult to perfume because the perfume must be adsorbed by the dispersed lamellar phase(s). When the percentage of dispersed lamellar phase(s) is lowered, without wishing to be bound by theory, less surface area is present for the adsorption of perfume oil. To further complicate this challenge, one skilled in the art may increase the perfume oil in such compositions to compensate for the reduced perfume deposition on fabrics. Thus the amount of oil that must be adsorbed is increased while the amount of surface area in the form of dispersed colloidal particles is decreased resulting in a situation wherein perfume incorporations is poor or near impossible even upon application of high mechanical energy.
There is a need for a wide range of perfume oils to be easily incorporated into compositions with very low to very high percents of dispersed lamellar phase(s) with little to no mechanical energy applied. There is a need to incorporate levels of perfume in fabric care products that require little or no mechanical energy.
There is a need for the concentrated perfume composition to have low flammability and/or low levels of water. One skilled in the art will appreciate that to maintain low costs in a product making environment, it is advantageous to utilize compositions that have low flammability, i.e., a high flash point (e.g., above 38° C.). Minimizing the water content (e.g., less than 10% water by weight of the composition) of the concentrated perfume composition is also advantageous. When water is present in the concentrated perfume composition, often mixing is necessary to maintain a homogeneous concentrated perfume composition.
There is also a need to provide a concentrated perfume composition that, in turn, can be added to an un-perfumed fabric care composition base as part of a late product differentiation processes.